Prokaryotic mechanosensitive channels mediate copper influx.

Copper is an essential micronutrient in all kingdoms of life, requiring a meticulous balance between acquisition and toxic overload. While copper import in eukaryotes has been investigated extensively, few prokaryotic copper importers have been identified, leading to the notion that cytoplasmic copper uptake is unnecessary in prokaryotes. Here we report that mechanosensitive channels are key players in prokaryotic copper import.

Prokaryotic mechanosensitive channels mediate copper influx.

Copper is an essential micronutrient in all kingdoms of life, requiring a meticulous balance between acquisition and toxic overload. While copper import in eukaryotes has been investigated extensively, few prokaryotic copper importers have been identified, leading to the notion that cytoplasmic copper uptake is unnecessary in prokaryotes. Here we report that mechanosensitive channels are key players in prokaryotic copper import.

The Escherichia coli AZY operon links copper uptake to antibiotic resistance.

Copper import to the bacterial cytoplasm has been underinvestigated as bacterial cuproenzymes are extracytoplasmic. However, copper must access the cytoplasm to interact with metal-dependent transcription factors. In particular, the multiple drug antibiotic resistance (mar) operon is induced by a copper signal, the source of which has not been established.

In depth, thermodynamic analysis of Ca binding to human cardiac troponin C: Extracting buffer-independent binding parameters.

Background: Characterizing the thermodynamic parameters behind metal-biomolecule interactions is fundamental to understanding the roles metal ions play in biology. Isothermal Titration Calorimetry (ITC) is a "gold-standard" for obtaining these data. However, in addition to metal-protein binding, additional equilibria such as metal-buffer interactions must be taken into consideration prior to making meaningful comparisons between metal-binding systems.